First it was former Maryland Gov. Martin O’Malley and Sen. Bernie Sanders of Vermont, who were both interrupted by protesters at last month’s Netroots Nation convention in Phoenix.

Now it is Hillary Clinton, whose frank and at times testy discussion with three Black Lives Matter activists in New Hampshire last week has begun to make the rounds on the Internet and cable television.

But the incidents speak to a deeper ferment among black activists, some scholars say. The Black Lives Matter movement that has helped catalyze sweeping changes in police policy nationwide since it began a year ago in Ferguson, Mo., is now setting its sights on the presidential race.

At this early stage, the effect is uncertain. But the black community has seen how high turnout in two presidential elections has contributed to victories for Barack Obama, while low turnout in two midterm elections has led to resounding victories for his Republican opponents in Congress. Black activists know the Democratic Party needs them, and the experience of the past year has only emboldened their resolve to be heard.

“I would say all the presidential candidates this year can be expected to be challenged on this issue,” Daunasia Yancey, who was involved in the conversation with Mrs. Clinton, told MSNBC.

The discussion between Clinton and Ms. Yancey and two other activists offered a revealing picture of how she and the activists disagree over tactics in the fight for equal rights.

In the video, Clinton essentially admonishes them for attempting to change hearts instead of laws.

“You’re not going to change every heart. You’re not,” she added. “But at the end of the day we can do a whole lot to change some hearts and change some systems and create more opportunities for people who deserve to have them.”

Another of the activists involved in the discussion, Julian Jones, told MSNBC’s Melissa Harris-Perry on Monday he thinks the encounter “moves the conversation on race in America to a newer and deeper level.”

The discussion itself points to a key fault line in current black political activism.

The question isn’t whether this new generation of black activism will have an impact, it is whether this activism will unfold inside the political system or outside it, says Clarence Lang, chair of African and African-American Studies at the University of Kansas.

“It seems that activists are poised to have an impact,” he adds. “What that impact will be I think is still an open-ended question.”

African-Americans are more than aware of the their electoral power, says Professor Lang, also author of the book, “Black America in the Shadows of the ’60s.” On her MSNBC show Monday, Ms. Harris-Perry said the Black Lives Matter movement “is here on the national stage to challenge those who want black votes. And guess which party really needs black votes?”

This renewed black activism is buttressed by growing support from other demographic groups.

A recent Pew Research Center survey found that 53 percent of white Americans think the country needs to continue changing to give blacks equal rights, an increase from 39 percent last year. In addition, a new Gallup poll found that 53 percent of whites said they are satisfied with the way blacks are treated in the United States, a drop from 67 percent in 2013.

While Lang agrees that black people may feel empowered politically, that doesn’t necessarily mean they feel empowered as voters.

“Do [black] people feel empowered as voters? That their vote will make a difference in upcoming elections?” he asks. “I don’t know.”

This may be why the activists are using direct action and interrupting campaign events to get their message across, Lang adds. He says he generally agrees with Clinton’s assertion from the video that, at the end of the day, concrete policy changes are all that matter.

But he says he supports how Black Lives Matter activists are pursuing policy changes.

“My argument would be that you get policy changes by doing what these everyday citizens are doing,” he said. “You create a crisis.”

These actions have already yielded some changes in campaigning by leading Democrats.

A few weeks after the protesters interrupted Mr. O’Malley, he released a new criminal justice policy calling for fixes to “our broken criminal justice system,” including ensuring “that justice is delivered for all Americans – regardless of race, class, or place.”

And earlier this month at a campaign event in Seattle, Senator Sanders ceded the stage to protesters. Later, he hired Symone Sanders – a young black criminal justice advocate – as his national press secretary. The candidate is already incorporating some of her suggestions into his campaign, she told Buzzfeed.

Lang says that these responses from candidates suggest that, “over the longer term, or maybe even the intermediate term, we might see some concrete” policy changes.